Natural language interfaces are more common today than they were at any other time, this is because of their use in industry and in homes. some examples include:
Apple.inc's Iphone 4s running IOS5 with Siri
Apple's iPhone's Siri. This recognises the sounds and words being made by analysing their sound waves and comparing it with a archive of sound waves which allows it to interpret what the sound waves are in the spoken language.
Google's Voice search on android phones and the Google Chrome browser
Google's Voice search on android phones and the Google Chrome browser